Evaluation of Reverse Tone Mapping Through Varying Exposure Conditions


Belen Masiá
Universidad de Zaragoza
Sandra Agustín
Universidad de Zaragoza
Roland W. Fleming
Max Planck Institute for Biological Cybernetics
Olga Sorkine
New York University
Diego Gutiérrez
Universidad de Zaragoza
Instituto de Investigación en Ingeniería de Aragón (I3A)

SIGGRAPH Asia 2009. ACM Transactions on Graphics 28, 5 (December 2009)

teaser


Abstract:
Most existing image content has low dynamic range (LDR), which necessitates effective methods to display such legacy content on high dynamic range (HDR) devices. Reverse tone mapping operators (rTMOs) aim to take LDR content as input and adjust the contrast intelligently to yield output that recreates the HDR experience. In this paper we show that current rTMO approaches fall short when the input image is not exposed properly. More specifically, we report a series of perceptual experiments using a Brightside HDR display and show that, while existing rTMOs perform well for under-exposed input data, the perceived quality degrades substantially with over-exposure, to the extent that in some cases subjects prefer the LDR originals to images that have been treated with rTMOs. We show that, in these cases, a simple rTMO based on gamma expansion avoids the errors introduced by other methods, and propose a method to automatically set a suitable gamma value for each image, based on the image key and empirical data. We validate the results both by means of perceptual experiments and using a recent image quality metric, and show that this approach enhances visible details without causing artifacts in incorrectlyexposed regions. Additionally, we perform another set of experiments which suggest that spatial artifacts introduced by rTMOs are more disturbing than inaccuracies in the expanded intensities. Together, these findings suggest that when the quality of the input data is unknown, reverse tone mapping should be handled with simple,non-aggressive methods to achieve the desired effect.

Direct Links:
[Paper] [Slides (18MB)]
New! Related publication: Multilinear Regression for Gamma Expansion of Overexposed Content [Paper]
Related publication: Selective Reverse Tone Mapping [Paper]
Related publication: Understanding Exposure for Reverse Tone Mapping [Paper]

BibTeX:
@ARTICLE{Masia09,
 author = {Masia, Belen and Agustin, Sandra and Fleming, Roland W. and Sorkine, Olga and Gutierrez, Diego},
 title = {Evaluation of Reverse Tone Mapping Through Varying Exposure Conditions},
 journal = {ACM Transactions on Graphics (Proc. of SIGGRAPH Asia)},
 year = {2009},
 volume = {28},
 number = {5},
 pages = {160:1--160:8},
 }
@techreport{Masia11,
 author = {Masia, Belen and Gutierrez, Diego},
 title = {Multilinear Regression for Gamma Expansion of Overexposed Content},
 institution = {Universidad de Zaragoza (Technical Report RR-03-11)},
 year = {2011},
 month = {July}
 }
@INPROCEEDINGS{Masia10,
 author = {Masia, Belen and Fleming, Roland W. and Sorkine, Olga and Gutierrez, Diego},
 title = {Selective Reverse Tone Mapping},
 booktitle = {Congreso Espa\~{n}ol de Informatica Grafica},
 year = {2010},
 publisher = {Eurographics}
 pages = {},
 }
@INPROCEEDINGS{Martin08,
 author = {Martin, Miguel and Fleming, Roland W. and Sorkine, Olga and Gutierrez, Diego},
 title = {Understanding Exposure for Reverse Tone Mapping},
 booktitle = {Congreso Espa\~{n}ol de Informatica Grafica},
 year = {2008},
 publisher = {Eurographics}
 pages = {189--198},
 }